Building-block.



E. L. DOBBINS.

BUILDING BLOCK.

AIPLIOATION FILED FEB. 14, 1908.

Patented Mar. 5, 1912.

$1 4/ 2/2 g p/ Q/ Z M EDWARD L. DOBBINS, or JEWELL, KANSAS;

BUILDING-BLOCK.

Specification of Letters Patent.

' Patented Mar. 5, 1912.

Application filed February 14, 1908. Serial N5. 415,933.

To all whom; it may concern:

Be it known that I, EDWARD L. DoBBINs, a citizen of the United States,residing at Jewell city, in the county of Jewell, State of Kansas, haveinvented certain new and useful Improvements in Building-Blocks; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

The present invention relates to improvements in cement building blocks,and more particularly to articles of that class designed especially foruse in the construction of chimneys, it being the general object of theinvention to provide a series of such blocks adapted when mounted oneupon another, to form a chimney which is to all intents a single solidhomogeneous structure.

To this end, the invention resides in the provision of a cement blockcomprising spaced inner and outer walls and a series of spaced membersconnecting the same and cast or molded integral therewith, the upper andlower faces of said members being spaced from the corresponding edges ofthe walls so as to form cement receiving cavities between said wallswhich communicate with the spaces between said members, thus permit-tingthe cement to fill said cavities and spaces and form a monolithic lockbe tween the superposed blocks.

The invention will be readily understood from a consideration of thefollowing detailed description, and its preferred embodiment isillustrated in the accompanying drawings, in which corresponding partsor features, as the case may be, are designated by similar referencenumerals in the several views.

Of the said drawings: Figure 1 is a perspective view of the improvedblock. Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1.Fig. 3 is a vertical section taken on the line 33 of Fig. 1.

Referring more particularly to the drawings, the block illustratedtherein is shown as comprising a rectangular inner wall 5 surrounded byand inclosed within a similarly-shaped outer wall 6, said walls beingarranged in spaced relation to each other i and connected together bycorner pieces 7.

The walls and corner-pieces form an integral structure which is cast,molded or otherwise constructed as preferred.

The corner-pieces are L-shape'd in horizontal cross section. The heightof one wall is equal to that of the other wall, while the height of thecorner-pieces is less than that of the walls, as shown, the upper andlower faces of the corner-pieces being in consequence, spaced fromthecorresponding edges of the walls, the upper faces of the cornerpieceslying below the upper edges of the walls, whose lower edges extend belowthose of the corner-pieces.

The open spaces 9 between the cornerpieces, as well as the open spacesor cavities 8 between the upper and lower faces of the corner-pieces andthe corresponding edges of the walls, are adapted to be filled by abinder 10 of plastic cement, as hereinafter described.

In the construction of the chimney, the blocks are superposed one uponanother, until the required height is reached; plastic cement is thenpoured through the openings 9, filling the same and the mating openspaces or cavities 8 between adjacent blocks. The cement binder onsetting thus forms a solid monolithic lock between the blocks, as willbe apparent, the provision of the spaces or cavities 8 affording amaterially increased area of contact for the cement with the blocks and'proportionately strengthening the joint between the same.

The space inclosed by the sides of the inner wall of the completedchimney forms a passage 11, for the products of combustion.

While'the blocks are designed primarily for use in the construction ofchimneys it is to be understood that they may be used. with equalfacility in the construction of culverts and drain pipes, in whichlatter instance, the inner and outer walls of the block are in the formof concentric circles in cross section, as shown in Fig. 4:.

What is claimed is:

1. A building block for chimneys comprising a unitary structure havingan outer wall, an inner wall concentric with and spaced from the outerwall, said inner wall being of equal height to the outer wall and theterminal faces of said inner and outer walls lying in the same plane,spacers between said inner and outer walls and spaced around the innerwall, the terminal faces of said spacers being spaced from the adjacentterminal faces of the walls at equal distances, and the confrontingfaces of said Walls being beveled continuously from the planes of theterminal faces of the spacers. 2. A structure comprising a series ofsuperposed building blocks each comp-rising a unitary structure havingan outer wall, an inner wall concentric with and spaced from the outerwall, said inner Wall being of equal height to the outer wall and theterminal faces of said inner and outer walls lying in the same plane,spacers between said inner and outer walls and spaced around the innerwall, the terminal faces of said spacers being spaced from the adjacentterminal faces of the walls at equal distances, and the walls wherebythe filling is provided with a series of opposed pairs of lnner andouter circumscribingribs constituting means to lock the blocks firmlytogether.

In testimony whereof, I affix my signature, in presence of twowitnesses.

EDWARD L. DOBBINS.

Witnesses:

WM. G. MOINTYRE, E. A. BODDING.

Copies of this patent may be obtained for five cents each,by'addressi'ng the Commissioner of Patents, Washington, D. G.

